It is now possible to disable Inline Form Errors (IFE) for a specific form when the module is enabled. This is an addition to the Form API.
Before
It was not possible to disable IFE.
After
Set the #disable_inline_form_errors
property to TRUE
on the top level of the $form
array.
$form['#disable_inline_form_errors'] = TRUE;
Warning
This should only be done when another appropriate accessibility strategy is in place.
Example use case
A good example of when this is needed is the Quick Edit interface. It has alternative error reporting which is user friendly and accessible.
More info
More information about Inline Form Errors, known limitations and for example disabling error messages for a single element can be found in the Inline Form Errors documentation.